1. Field
The subject matter disclosed herein relates to cache memory systems. In particular, the subject matter disclosed herein relates to the dynamic replacement of data items in cache memory systems.
2. Information
A processing system typically hosts procedures to process data which is stored in a system memory. Such a processing system typically retrieves instructions and data items from the system memory by initiating requests to retrieve data located in the system memory at a system memory address. Similarly, a processing system may store data in the system memory by initiating requests to store data in the system memory at a system memory address.
Following a request by a processing system to either store data in or retrieve data from a system memory, a latency typically follows such a request before such a storage or retrieval is completed. In the case of a request to retrieve data, a processing system may suspend execution during such a latency until the requested data is received for processing. Longer latencies following a request to retrieve data may therefore degrade real-time performance of such processing systems.
In addition to a system memory, a processing system may comprise one or more cache memories to store data which may be retrieved with a shorter latency than a latency associated with retrieving data from the system memory. To improve performance of the processing system, certain data items in the system memory which are expected to be accessed frequently may also be stored in the cache memory to reduce latencies associated with retrieving these data items.
Portions of data stored in a cache memory may be dynamically replaced with data items in the system memory. These data items in the system memory may be expected to be accessed by the processing system with greater frequency than data items in the cache being replaced. How data items in a cache memory are selected for replacement can affect the performance of a processing system to the extent that subsequent accesses to the replaced data items may introduce increased latencies over accessing the replaced data items from the cache memory.